The National Weather Service Office in Missoula has declared a flood watch for western Montana starting at 3:00 p.m. on Monday and continuing through late Tuesday night.

Meteorologist Corby Dickerson said a powerful storm system has been gathering in the northern California and northern Nevada areas and will produce heavy rains as it reaches the northern Rockies.

"This rain will start overnight tonight and will last on and off through tomorrow and into Wednesday morning," Dickerson said. "The result of that one to two inches of rain, combined with the fact that we still have some snow up in the higher elevations, will produce some rapid rising in area creeks, culverts and streams, and ultimately leading to a pretty steady rise on the Bitterroot  and Clark Fork Rivers."

Dickerson said he expects very minor flooding, but the levels will rise rapidly once the rain storms arrive.

"Over the next 36 to 48 hours we can expect to see some increases in water levels due to the increase water flows over the next few days," he said. "When we get into this situation, it's mainly the creeks and streams that will see the most aggressive response. Fortunately, it's a little early in the year to be floating the rivers, but if folks will be near the water, be cognizant that the rain will be pushing those up a bit. Rivers will be swift with lots of debris."

Dickerson said the fast moving storms will cause rapid changes in conditions near creeks and streams.

"This amount if rain in this short a time is going to cause a pretty quick change, and it could push some of those streams briefly out of their banks, and maybe overwhelm culverts for a period of time where the water goes under the roads," he said. "It's localized and more specific than main stem flooding."

The National Weather Service says rapid river rises are expected on the Bitterroot River and on Rock Creek. Noticeable river rise expected on the Clark Fork River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Watch means there is a potential for flooding based on current forecasts.

You should monitor later forecasts and be alert for possible

Flood Warnings. Those living in areas prone to flooding should be

prepared to take action should flooding develop.

More From Newstalk KGVO 1290 AM & 98.3 FM